Abstract #1630

fMRI using High Flip-Angle Alternating Steady State Balanced SSFP Supported by Monte Carlo Studies

Steven Andrew Patterson^1,2, Steven Donald Beyea^1,3, Chris Van Bowen^1,3

¹Institute for Biodiagnostics (Atlantic), National Research Council Canada, Halifax, Nova Scotia, Canada; ²Physics, Dalhousie University, Halifax, Nova Scotia, Canada; ³Physics, Biomedical Engineering & Radiology, Dalhousie University, Halifax, Nova Scotia, Canada

To achieve artifact-free whole brain coverage and good temporal resolution using passband balanced SSFP (pbSSFP) functional MRI (fMRI), alternating between two steady states to eliminate banding artifact is necessary. Monte Carlo simulations of alternating steady state pbSSFP (altSSFP) fMRI were conduced to characterize BOLD signal and contrast. Results suggest altSSFP can provide artifact-free whole brain coverage with 2-3 s temporal resolution and up to 90% of the BOLD contrast observed in conventional pbSSFP if high (45-60) flip angles and linearly increasing flip angle RF catalyzation is used. Despite off-resonance signal intensity variation, spatially-uniform sensitivity fMRI maps are anticipated.